The present invention relates generally to pick assemblies used in the degradation of formations. The working life span of pick assemblies used for degradation applications is typically very limited, especially when engaging harder formations. As pick assemblies begin to wear their performance capabilities also begin to diminish. Consequently, many efforts have been made to extend the working life span of pick assemblies some of which are included in the following prior art references.
U.S. Pat. No. 5,417,475 to Graham et al., which is herein incorporated by reference for all that it contains, discloses a breaking or excavating tool that has a diamond and/or cubic boron nitride coated cutting insert mounted at the forward end of a tool body which is made of a softer material than the insert. A separately formed retaining member such as a washer, ring, or sleeve, made of harder material than the body, is brazed to a front face of the body surrounding the insert to protect the tool body against wear.
U.S. Pat. No. 3,807,804 to Kniff, which is herein incorporated by reference for all that it contains, discloses an impacting tool in which a massive hard carbide element is fitted to a steel holder which is reciprocated to drive the element against a formation to be broken. The massive carbide element can be press fitted in the steel holder or shrink fitted therein or brazed thereto and, furthermore, the carbide element can be fitted to a steel sleeve adapted for being secured to a steel holder as by threading or brazing.
U.S. Pat. No. 7,401,863 to Hall et al., which is herein incorporated by reference for all that it contains, discloses a pick that comprises a shank attached to a base of a steel body, a cemented metal carbide core press fit into the steel body opposite the shank, and an impact tip bonded to a first end of the core opposite the shank. The impact tip comprises a superhard material opposite the core, and the core comprises a second end and a largest diameter. A distance through the body from the shank to the second end of the core is less than the largest diameter of the core.